LECTURE 10 - Extrachromosomal Inheritance Flashcards
(21 cards)
Mendelian principles emphasized in eukaryotes, the genes controlling the phenotype is in the ______
however, there are important traits that can be controlled by genes in the _____
nucleus
cytoplasm
genes in the cytoplasm are _____ that act as agents for ______ _____
- extranuclear
- hereditary transmission
EXTRACHROMOSOMAL INHERITANCE
- states that the transmission of these cytoplasmic elements are dependent on????
- the transmission of cytoplasm from parents to daughter cells
does EXTRACHROMOSOMAL INHERITANCE follow mendelian laws?
No
MATERNAL INHERITANCE
- a characteristic _____ in the results of a _____ ______ where the progenies show characteristics of their ___ parent
+ reason for this
- implies transmission through the ______
- difference
- reciprocal cross
- female
- female gamete contributes the majority of the cytoplasm to the zygote
- cytoplasm
NON-MAPPABILITY
- the (inability/ability) of genes to show ______ (thus also affects the genes capability to be _____ )
- linkages
- mapped
*also shows extrachromosomal inheritance
NON-SEGREGATION
- failure to show this under appropriate circumstance indicate ______ ______
extrachromosomal inheritance
NON-MENDELIAN SEGREGATION
- states that when segregation occurs _____ with _____ segregation, ____-______ factors might have accounted for the phenotypic ______
- inconsistently
- chromosome
- non-chromosomal
- variation
INFECTION-LIKE TRANSMISSION
- a ____ phenotype is transmitted (with/without) nuclear transmission; it seems _____ that ____ control the phenotype
- heritable
- without
- unlikely
- chromosomes
INDIFFERENCE TO NUCLEAR SUBSTITUTION
- when heritable characteristics persist in the presence of nuclei known to have been associated with alternative characteristics, the ____ of ______ genetic material over the ____ may be ____ ____
- control
- nuclear
- characteristic
- ruled out
the inheritance of CHLOROPLASTS was first reported in ____ by _____ ____ in _____ ____ of ____ ____ plants
1909
Carl Correns
Mirabilis jalapa (underlined) of four o’clock plants
CYTOPLASMIC INHERITANCE OF CHLOROPLASTS
- leaf color includes (3)?
- follows ___ inheritance
- green
- white
- variegated (patches of green and white)
- maternal inheritance
nuclear / chromosomal genes
VS
cytoplasmic / extrachromosomal genes
N/C
- carried by chromosomes housed in nucleus
C/E
- carried by DNA housed in organelles (chloroplast & mitochondria) found in cytoplasm
CRITERIA FOR IDENTIFYING EC GENES
- difference in result of reciprocal crosses
- maternal inheritance
- non-mappability
*do not show predictable linkage patterns - non-segregation
*expected gamete ratios are not shown in individuals - non-mendelian segregation
*doesnt follow the usual laws - indifference to nuclear substitution
*nuclear substitution does not affect phenotype of EC genes - infection-like transmission
*if an EC gene is infected to another cell, it would start and infection-like effect on new cell
which of the germ cells contribute to the ff:
- cytoplasm of zygote
- organelles of zygote
both are egg cells
the term used to describe the superiority of the F1 over its parents in terms of yield or other characteristics?
+ relevance in crop farming?
heterosis/hybrid vigor
since yung F1 gen have better phenotypic characteristics than parents, CROSS-POLLINATION must be done (and selfing is prevented) to produce better quality crops
how can selfing in crops be prevented?
emasculation or detasseling
in corn, CYTOPLASMIC MALE STERILITY is due to a gene in the ______ called the ____ gene
those with this gene will have ______ ______ ______ wherein ______ is NOT POSSIBLE
+ what type of gene can reverse this effect?
- mitochondria
- S gene
- sterile male flowers
- selfing
“restorer gene” so those that have RR or Rr gene are male fertile flowers
GENETIC BASIS OF HETEROSIS (3)
- Dominance
- accumulation of favourable dominant genes in the hybrid - Overdominance
3, Epistasis
- non-allelic interaction
refers to when mitochondrial DNA is inherited from only the mother
+ if both from father and mother?
+ this result is found in what study?
+ how many individuals showcase biparental mitochondrial transmission?
+ ^^ individuals showed what syndrome?
Homoplasmy
Heteroplasmy
- Lou et al.
- 17 individuals
- Leigh Syndrome
what mechanisms (2) are used to remove paternal mitochondria?
+ using what enzyme?
- lysosomal pathway
- autophagy
mitochondrial endonuclease G*
*nuclear genes involved in coding this are mutated in those with Leigh Syndrome
